This invention relates in general to surgical scissors, and in particular to a surgical scissors instrument having cooperating cutting blades and disposed at their distal ends are two forceps jaws comprising bipolar electrode structures which can function to coagulate tissue immediately prior to its being severed by scissor action of the cutting blades
Electrocauterization is a process whereby blood vessels (commonly called "bleeders") in tissue or alone which are cut during a surgical procedure are sealed closed by applying electrical energy at the site to, essentially, fuse by heat the vessel opening. To provide electrical energy at the site of bleeding, an instrument capable of conducting electricity must be placed at that site. The conductive instrument may be comprised of one electrode (monopolar) which cooperates with a remote conductive body plate electrode, or the instrument may be comprised of two closely spaced electrodes (bipolar). Current passing from one electrode to the other produces the heat sufficient to seal blood vessels or to coagulate blood and other fluids so coagulable. A bipolar instrument is generally preferred by a physician since current travel is over a short distance and is predictable. A monopolar instrument usually requires electric current to travel a relatively long distance to the body plate electrode, with current directability and effect being unpredictable and possibly harmful to a patient.
Electrosurgical scissors and electrosurgical forceps individually are known in the art. Additionally, in U.S. Pat. No. 5,342,381, issued Aug. 30, 1994, commonly assigned and incorporated herein by reference, the applicant thereof describes a combination bipolar scissors and forceps instrument comprising two blade members which are configured to form forceps jaws at their distal ends and scissors blades proximal to the jaws. The entire blade members, both forceps and scissors portions, are electrically conductive, with the scissors blades electrically insulated from each other along their interfacing surfaces. Thus, both the forceps portion and the scissors portion function to coagulate tissue.
While the combination scissors and forceps instrument described above is highly effective in most surgical procedures, a physician may desire a concentration of electrical energy only at the distal ends or tips of a scissors instrument instead of having electrical energy present in the entire blade structures. Delivery of energy only distally permits the physician to exercise a more precise control of coagulation activity.
It is therefore a primary object of the present invention to provide a surgical scissors instrument having at its distal end bipolar electrode structures which function to coagulate tissue immediately prior to tissue severance by the blades of the scissors which are electrically passive.
Another object of the present invention is to provide a surgical scissors instrument wherein distally-disposed electrode structures extend distally from respective electrically insulated housings which also have secured thereto the cutting blades of the scissors.
Yet another object of the present invention is to provide a surgical scissors instrument wherein distally-disposed electrode structures additionally function as jaws of a forceps.
These and other objects of the present invention will become apparent throughout the description which follows.